Forces have reportedly been told that they need to tackle the issue as a matter of urgency, with figures obtained by the newspaper from 38 of the 43 forces in England and Wales showing that 169 officers, police community support officers (PCSOs) and support staff are under investigation.

It comes after a number of cases of officers abusing their position to carry out sexual assaults or make inappropriate advances to members of the public and vulnerable victims of crime.

The Independent Police Complaints Commission (IPCC) said it is currently overseeing just 31, or 18%, of the cases.

IPCC chairwoman Dame Anne Owers said: "Police who abuse their position and exploit women for sexual gratification have no place in the police service.

"While these cases are rare, each of them is a fundamental abuse of power, and therefore seriously undermines public trust.

"It is clear that a small number of officers and staff continue to target vulnerable individuals, often women.

"The IPCC has 31 ongoing investigations into abuse of powers cases, the majority of which are being supervised by our corruption team.

"We are encouraged by the positive responses of police forces to this issue and the fact that more referrals are coming to the IPCC demonstrates a willingness to root out this type of behaviour.

"We are currently awaiting the Home Secretary's proposals on the expansion of the IPCC and welcome the opportunity to extend and strengthen our work.

"As more resources become available the IPCC will aim to investigate more abuse of powers cases independently of the police service."â?¬

CID officer Jeffrey Davies, 42, was found guilty last week of sexually assaulting two female victims who came to him to report crimes.

He will be sentenced on August 15 after a jury at Swansea Crown Court took little more than four hours to convict him of two separate sex assaults.

Last month Detective Constable Clifford Earl, 57, was jailed for 12 months for sexually assaulting two women in their own homes while on duty.

He molested a vulnerable and distressed innocent woman after police had arrested her partner in a dawn raid, having remained behind alone to comfort her and take a statement.

The married father-of-two also kissed and begged another woman for sex in her own kitchen, while touching himself, after she went to police for help to solve the violent theft of her 11-year-old son's bike.

Steve White, vice chairman of Police Federation of England and Wales, said: "Officers have to abide by a strict code of conduct and are expected to behave with the utmost professionalism.

"Clear measures are in place to deal with this kind of behaviour and it is quite right that officers have to go through that process."